Attaching device and molded member containing the same



Feb. 21, 1928. V 1,659,927

J. S. STULL ATTACHI'NG DEVICE AND MOLDED MEMBER CONTAINING THE SAME Filed Sept. 28, 1923 In venioi" Jbhn J. Jiull Patented Feb. 21, 1928.

UNITED STATES PATENT OFFICE.

JOHN STANLEY STULL, OF CHICAGO, ILLINOIS, ASSIGNOR TO WESTERN ELECTRIC COMEANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION 01? NEW YORK.

ATTACHING DEVICE AND MOLDED MEMBER CONTAINING TEE SAME.

Application filed September 28, 1923.

This invention relates to an improved means for securing a cylindrical insert in a molded or cast member so that the said insert cannot be readily removed therefrom.

The invention may be used to advantage in the manufacture of molded telephone mouthpieces in which a threaded member, by which the mouthpiece is attached to the telephone transmitter, is made in the form of a cylindrical insert which is molded into the body portion of the mouthpiece, the present invention providing an anchoring means for this insert of such a character that the insert cannot be readily detached from the mouthpiece, the union being so strong that in most instances the insert can only be removed by destroying the mouthpiece.

Another object of the invention is to provide anchoring means of the character above described, so designed that it does not appreciably add to the cost of the tubular member or the insert.

Other objects and advantages of the present improvement will appear in the following description and will be particularly pointed out in the appended claims.

In the accompanying drawings, which illustrate the invention as embodied in the attaching means of a telephone transmitter,

Fig. 1 is a vertical sectional view of a telephone mouthpiece having an attaching, means made in accordance with the invention;

Fig. 2 is a section taken on the line 22 of Fig. 1 looking in the direction indicated by the arrows, and

Fig. 3 is an enlarged perspective view of the attaching means.

In the drawings 5 indicates thebody portion of the mouthpiece and 6 the attaching means. The body portion 5 may be made 0t any suitable material. but preferably of a moldable material such as a synthetic resin, shellac composition, or rubber. In order that the mouthpiece may be readily cleaned, as by sterilizing in hot water, a synthetic resin formed from phenol and a suitable catalyst such as formaldehyde and ammonia or hexamethylenetetramine is preferably used as the molding composition. This material is inert to most solvents, is infusible, and does not discolor with age. p

The attaching means 6 may be assembled with the body portion 5 in any suitable manner, but is preferably molded into the body Serial No. 655,507.

portion as an insert. The attaching means 6 is preferably made of brass or other metal and is tubular in form, which is counterbored to form a flange 10 to receive the molding compound and form a support 11 for the usual perforated partition 12-. The outer surface of the attaching means 6 is provided with screw threads 8 and 9. The threads 8 serve as a means for holding the attaching means within the body portion, as is readily understood, while the threads 9 provide a means for attaching the mouthpiece to the telephone transmitter.

To prevent the attaching means 6 from being screwed out of the body portion on the threads 8, the upper edge of the attaching means is roughened, as indicated at 13, to serve as an anchor. The roughing prcterably takes the "form of knurling which may be of any suitable depth to anchor the insert. The attaching means may be knurled at practically no additional expense during the counter-boring operation to form the internal flange 10.

"What is claimed is:

1. The combination with a molded member, of an attaching device therefor comprising a cylindrical member having external threads throughout its length, a portion of which is embedded directly in the molded member, and a plurality of closely spaced projections forming an extension of the cylindrical surface to distribute the torsional stresses around the periphery of the molded member.

'2. The combination with a molded member of acylindrical member molded therein, said cylindrical member having external screw threads and one end thereof being knurled to provide projections, said projections being embedded within said molded member.

3. A mouthpiece comprising a bod" tion and an attaching means compri a metallic tubular member embedded in the said body portion, said tubular member having external screw threads, the upper edge of the said tubular member being knurled to provide an anchoring means.

In witness whereof, I hereunto subscribe my name this 17 day of September A. D, 1923.

poc-

JOHN STANLEY STULL. 

